The general-purpose PLC and the controller that individually controls a program dedicated to the machine and the like can be cited as an example of the controller that is used to control the operation of the machine or the facility.
For example, the PLC is constructed by a plurality of units, and the plurality of units include a CPU (Central Processing Unit) unit that includes a microprocessor executing a control program and an IO (Input Output) unit that inputs a signal from an external switch or sensor and outputs the signal to an external relay or actuator. The PLC executes control operation while data is exchanged between the units through a PLC system bus and/or a field network in each control program execution cycle.
The controller support device is used to generate various pieces of setting information on the controller and the control program executed by the controller, and to transfer the various pieces of setting information to the controller. For example, the controller support device is constructed by installing a controller support program on a general-purpose computer. For example, the controller support device includes an editor function of generating a source list of the control program, a compiler function of generating an object program operating in the controller from the source list of the control program, a controller simulator function of performing a test of the control program in the controller support device, and a communication function with the controller.
In a control program development stage, it is necessary to know an execution time necessary for the controller to execute the control program. The control program execution time is referred to when duration of the control program execution cycle is determined.
Japanese Unexamined Patent Publication No. 2001-209411 (Patent Document 1) discloses a method for obtaining the execution time in the PLC support device when the control program is executed by the PLC. Specifically, actual processing time data of each command used in the control program is prepared in the PLC, the actual processing time data is referred to every time each command is processed during program simulated execution processing of a simulator, and the actual processing time corresponding to the command is integrated. Patent Document 1 also discloses a method for obtaining an execution required time in each task when the whole control program is constructed by a plurality of divided tasks.